Mark & Stu I would not hesitate to do it to a collector grade Luger at all. You can get the kits from
Brownell's . You load these very light so the bullet just exits the barrel. True it does remove metal, basically it accelerates wear. However it has been proven to increase accuracy and makes cleaning the barrel much easier. I would guess on a lightly frosted bore you might remove about .001". Not a lot, but makes a big difference.